#include <fstream>
#include <iostream>
#include <string>

using namespace std;

int main() {
    ifstream in("casar.txt", ios::in);
    if (!in) {
        cout << "error opening file casar.txt" << endl;
        return 0;
    }

    char c;    
    while (in.get(c)) {
        c -= 3;
        cout << c;
    }

    in.close();

    return 0;
}